Choosing The Right Air Compressor

So here I am again with a second part of my series that I’ve started recently. First part was about airbrush guns, where I described all the types of airbrush guns that exist out there on the market and I’ve brought a few professional advises that I believe could help you to choose the right airbrush gun.

But airbrushing can not be possible without the proper air source. The air has to be at certain pressure to allow us to work. Every gun has different demands on its properties, so it is really relevant which air compressor you will choose for your airbrush gun.

What I decided to do here is to write all about compressors. Why? So you can learn something more than just listen to some advises.

First of all I want to mention some properties that have effect when choosing the air compressor.

One of very important parameters for compressor is PSI (Pounds Per Square Inch). It stands for pressure and is used in conjunction with air flow capacity CFM (cubic feet per minute). When comparing Pressures and CFM between units we have to use both CFM and PSI at the same time (example: 17 CFM @ 175 PSI, or 6 CFM @ 90 PSI). This can vary and it depends on type of paint you are going to work with and type of airbrush gun.

Usually when you buy an airbrush gun it has given a property CFM from air source which gun requires to its proper functionality. That very same property we can find in the specification of air compressor in conjunction with PSI.

You have to choose compressor that has same or better (higher) CFM than your gun.

These are probably the most important data you have to look for when buying the compressor.

2. Airbrush Gun

But be careful as every type of airbrush has its use. So if you are going to do detail work but at the same time planing to do something bigger and planing to use more than one airbrush you have to choose really good compressor. Mostly every beginner is planing on trying only, so using more than one gun is not affordable, I believe.

Your final decision on compressor could be made only after you decide on airbrush gun.

That’s why a lot more skilled artists with limited finances are choosing to build their own compressor. This is not a bad option, but in this article we concentrate on the buying a new one as I don’t expect my readers to be good in this stuff and have this kind of skills (well not every one).

3. Noise

Very important factor to consider. A noisy compressor can make your life miserable. You have to find the compressor that has acceptable level of noise for your work.

Recognise that the lower cost compressors, and many expensive ones for that matter, are very noisy. It is pretty hard to concentrate on doing the right colour blend when all of sudden the compressor jumps into life, scaring the crap out of you, and your steady hand jerks away, that can ruin your whole work in one second.

I think that one of the most important thing for an airbrush compressor is that it has to be quiet.

It can go on with almost no sound, and go off with some “psssss” or you can hear clacking of pressure switch, max. That quietness does not come very cheap. The high cost for a quiet compressor could scare you off and you will purchase some cheap compressor and then spend some money building a sound proof box around the thing. If you do that, make sure you leave good air access to allow cooling of the compressor.

4. Water

All compressors generate water and water vapour! Regardless of the type of compressor you purchase, water spraying out of your nozzle will destroy all your paint work. So usually we use filters that can remove the water from the air and point-of-use dryer to remove water vapour and to ensure that no water can reach your work.

5. Regulators

Regardless of the type of compressor you buy or build, one thing you will want to have is a precision regulator. Using a precision regulator means that you can set the correct pressure that works best with your gun and your paint mix, so the precision regulator will ensure that flow is consistent and steady.You may noticed that the point-of-use dryer

and regulator is the same unit doing a few functions at ones.

6.Duty cycle.

Always take a look on air compressor duty cycle, and do make sure that the compressor you purchase has enough flow capacity at the pressure you need, so that it can rest as often as necessary to ensure long life.

This is quite an important information to have when you are sizing your compressor. Many compressors are not meant to run all the time. Some need to have a rest period of a certain percentage of operating time to give the unit time to cool down. You have to be aware of that to prevent breakdowns and to prolong the life of your compressor.

Usually, the duty cycle is expressed as a percentage of a certain time frame, that often being a 10 minute.

A duty cycle of 50% would mean that this compressor could run for half an hour, and then must have a 30 minute rest period before it goes on to compress more air into the tank. It’s often the homemade diy that gets caught in the compressor duty cycle trap. Not knowing what the duty cycle of their compressor is, and burning it out because of long use. Industrial compressors often have a 100% duty cycle, meaning they can run continuously without a cool down period.

Check carefully! A compressor that has great flow capacity for your airbrush, might run well beyond its duty cycle when it’s being used on a big job at home, leading to maintenance issues which are easily avoided. So be sure of the duty cycle before you buy. The manual that comes with your compressor should indicate the duty cycle. The problem is that some doesn’t. If you’re not sure, and plan to use your compressor for long periods, try to contact manufacturer by e-mail or phone to ask them directly.

TYPES OF COMPRESSORS

Some of the compressor types you will run into on the market:

Reciprocating Piston

Rotary Vane

Rotary Screw

Portable

AirBrush

HomeMade

Reciprocating Piston Compressors

Reciprocating (piston) air compressors are the ‘work-horse’ compressors with which you’ll likely be most familiar.

You’ll see them at the corner garage, on the shelves at the hardware stores, in residential garages, many home basements, everywhere.

Careful! Reciprocating compressors often have the lowest prices, but the highest operating cost! If you’re planning on using a lot of air in your studio, a different types of compressor may give you better option over the long time.

Rotary Vane Compressors

Vane compressors use “air-tool” type technology to compress air. These compressors are used in a variety of applications

Rotary Screw Compressors

The Rotary Screw compressor manufacturers state that their technology is the right choice for many industrial applications.

Portable Air Compressors

Many times you’ll need compressed air at a site where there aren’t any air mains, and where the common plant electrical supply is not available to run the compressor.

All compressor types theoretically work more efficiently if they are designed to include multiple stages.

Well as you can get, I’ve described the types of air compressors and we don’t have to consider all of them. As I have mentioned before what is going to interest us is AirBrush compressors, or maybe someone would like to try (diy) homemade compressor.

Airbrush compressors

Even here we have more types to choose from.

Oil-less

Does not require any oil for a run. Some people will point it out that this type of compressor is a must have compressor for airbrushing. As it doesn’t spit the oil on your masterpiece. Well that’s truth, but this types have their minuses. They could be noisy and overheat very quickly. A hotter running compressor usually means more maintenance and shorter compressor life too.

Diaphragm

Some of this compressors don’t have a steady airflow (I call it pulsing air flow). This could be compensated with a tank (receiver). If your airbrush is gravity feed and you are using very thin paint you can give it a try. (example Paasche D500SR can be used with airbrush gun Paasche VL). Diaphragm compressors achieve compression with the use of a flexing diaphragm that moves back and forth in a closed chamber. The design is an alteration of the reciprocating piston concept. The motion of the connecting rod under the diaphragm causes the flexing and only a short stroke is needed to generate similar pressure effects as those of a reciprocating piston compressor.

Piston

This one is good for gravity feed fixed nozzle and thin colours (Comart, Golden Airbrush)

Single piston (SprintJet)

Double piston in Metal Case (PowerJet) – good for home or apartment. They are “quite” but will not work with thick paints (high viscosity – textile colors with floating nozzle). I used quotation marks because it is not really quite (check some videos on youtube).

Silent Air 1/2 horse power compressor has enough PSI to work with textile colours and can be great for art work, but it has not enough air for base coating or clear coating (Silent Air makes more powerful compressors that are good for coating but they are more expensive).

Fridge compressor with tank (Iwata Great White Shark) is airbrush compressor (because it uses fridge type compressor it’s really very quite). It can run up to 3 airbrushes at the same time with almost no problem. But this quality costs big money :(

Little or Big Compressor?

Another question is how big compressor you can afford? Other than the obvious differences in size, the really important difference to the compressed air user is the differing capacity of these compressors (the compressor’s ability to deliver compressed air at a certain CFM and a certain air pressure at that specific CFM of flow).

Yes, the 12 VDC unit plugged into your car’s power supply can give you 120 PSI air (depending on the brand of course) just like the 40 HP compressor can, but they are suitable for low flow applications only.

If you tried to use this type of air compressor for a high-demand application, the compressor could never catch up (compressed air outflow would always exceed the compressor’s ability to compress it) and it would never reach cut out pressure to allow it to shut down.

The small compressors have a limited duty cycle, so it would run at full capacity trying to supply enough air for a high-demand application until it will self-destruct. Compressor capacity is critical to your compressor selection.

All compressors do essentially the same things. They “suck” free air, and compress it up to the pressure limit that is specified by the unit. You have to select the type of compressor that delivers the capacity you need, both in terms of pressure and the flow of compressed air at the pressure your application requires.

One of the options is to buy an industrial compressor from any Home department store. It will work with regulator and filter that you can attach to them but they are very noisy, so before you buy any, ask to hear it.

Make sure that the unit you select has good flow and good pressure for your painting needs.

Don’t forget to drain the receiver regularly to eliminate free water from the tank (if you have any), and also remember that the liquid you drain is now considered as a hazardous waste as it contains water and oil, and should be disposed of properly.

Actually during my research I have found that some companies that produce airbrush guns and compressor will recommend you which compressor could be used with the gun you bought from them. Here is the table from IWATA that even recommends their equipment depending on your level of skills in airbrushing.

I think that you may get the feeling that I’m promoting one brand. Well I was trying not to, but that is my own experience and I think they deserve it. By the way I’m not getting any money from them for mentioning their name. Here are some advises from professionals:

Well You can buy Oil-less compressor and be happy with that. But don’t be surprised that one day it will burn out (of course it depends on how you going to maintain it).

I think that it is good if you oversize your compressor (buy a bigger one). And use a pressure regulator to set the output pressure by your needs. It will give you more freedom, no matter if you work with thin nor thick colours or you use different gun.

Instead of buying an oil-less compressor, simply ensure that the air that exits the oil-lubed compressor is adequately filtered to remove free water and oil.

I think that pressure regulator and filter is must have for any compressor.

Yes noise is important factor. Usually oil-lubed compressors are more quite than oil-less.

I’ve seen a lot of video reviews on youtube and a lot of those portable compressors are not that bad but only for small nozzle sizes. When it comes to 0.4 mm they have no chance. So I would recommend a compressor with tank.

I prefer homemade compressor. Fridge compressor has really low-level of noise comparing to any industrial piston compressor and tank is a big advantage here. Of course there one minus for tank – you have to wait a few minutes before you start painting as compressor has to fill the tank up first. But this is nothing when you see what it will give after that.

I hope that this article will help you somehow. My advice is, when you finally find the compressor you want to buy, find some reviews on it (could be even youtube video review). Try to join the conversation and ask other people what they think about that particular compressor and only then, when you have enough info, buy it. Good luck with your airbrush compressor hunt!

Related

Compression fittings are the industry standard for chemical, oil and gas, R&D, Bio-tech, and the semiconductor industry. They are used due to their ability to provide leak tight seals. These fittings can be remade.

Most people when they just starting don’t know much about the stuff a they buy first thing they find and after some time they spend more money whey they learn more. Garfield, do a good research before you buy your compressor ;)